ES3017057T3 - Firing system for linear surgical stapler - Google Patents

Abstract

A surgical stapler includes a first elongated element, a second elongated element, and a clamp that releasably holds the first elongated element against the second. The distal portion of the first elongated element supports an anvil surface with multiple staple cavities. The distal portion of the second elongated element is configured to house a staple cartridge. The surgical stapler's firing assembly moves from a first longitudinal position to a second longitudinal position to fire the staple cartridge when the first elongated element is clamped against the second. The surgical stapler's retaining assembly includes a first retaining element configured to releasably engage a proximal end of the first elongated element with a proximal end of the second elongated element, and a second retaining element configured to releasably retain the firing assembly in the first longitudinal position.

Description

DESCRIPTION

Trigger system for linear surgical stapler

Background

In some surgical operations, such as a gastrointestinal anastomosis, it may be desirable to clamp one or more layers of tissue, cut the clamped layers, and simultaneously introduce staples through the layers to substantially seal the severed tissue layers proximate their cut ends. One such instrument that may be used in such operations is a linear surgical stapler, also referred to as a “linear cutter.” A linear surgical stapler generally includes a first half (referred to as a “cartridge half” or “reload half”) having a distal jaw configured to support a staple cartridge (or “reload”), and a second half (referred to as an “anvil half”) having a distal jaw that supports an anvil surface having staple-forming features. The stapler further includes a movable clamping lever configured to releasably clamp the stapler halves together. The stapler halves are configured to rotate relative to each other to receive and clamp the tissue between the two distal jaws when the clamping lever is closed. A stapler firing unit is configured to be actuated to sever the clamped layers and simultaneously drive staples through the tissue on either side of the cut line. After the stapler is fired, the clamping lever can be opened, and the stapler halves separated to release the cut and stapled tissue.

US-2013/172929 A1 describes a surgical stapler with a first handle portion that may include a latching mechanism rotatably mounted thereon, which may be used to engage latching projections extending from a second handle portion and secure the first and second handle portions together. A locking mechanism may be configured to prevent, or at least inhibit, a drive bar from advancing distally before the latching mechanism moves to a predetermined position, such as, for example, a closed position and/or a partially closed position.

Summary of the invention

The present invention provides a surgical stapler as recited in claim 1. Optional features are recited in the dependent claims.

Brief description of the drawings

The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate surgical devices including embodiments of the invention and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.

Figure 1 illustrates a distal perspective view of an exemplary linear surgical stapler that does not include a retention unit as required by the invention, showing a cartridge half and anvil half of the stapler coupled together with a cartridge half clamping lever in a fully closed position;

Figure 2 illustrates an exploded perspective view of the linear surgical stapler of Figure 1;

Figure 3 illustrates a cross-sectional perspective view of a staple cartridge unit of the linear surgical stapler of Figure 1;

Figure 4A illustrates a cross-sectional side view of the linear surgical stapler of Figure 1, showing the stapler halves coupled together at their proximal ends with the clamping lever in an open position;

Figure 4B illustrates a cross-sectional side view of the linear surgical stapler of Figure 1, showing the stapler halves engaged together with the clamping lever in a partially closed position; Figure 4C illustrates a cross-sectional side view of the linear surgical stapler of Figure 1, showing the stapler halves engaged together with the clamping lever in a fully closed position; Figure 5A illustrates a distal perspective view of the linear surgical stapler of Figure 1, showing a stapler actuator in a proximal, pre-fired position;

Figure 5B illustrates a distal perspective view of the linear surgical stapler of Figure 1, showing the actuator in a fired distal position;

Figure 6 illustrates a distal perspective view of another exemplary linear surgical stapler according to the invention, showing a cartridge half and anvil half of the stapler coupled together with a cartridge half clamping lever in a fully closed position;

Figure 7 illustrates an exploded perspective view of the linear surgical stapler of Figure 6;

Figure 8 illustrates a perspective view of a proximal portion of the cartridge half of the linear surgical stapler of Figure 6, showing the clamping lever in an open position and revealing internal features of the cartridge half;

Figure 9 illustrates a perspective view of a proximal end of the cartridge half of Figure 8, showing a side portion of a cartridge channel of the cartridge half partially cut away to reveal a proximal retention unit including an anvil engaging member and a retainer member;

Figure 10 illustrates an exploded left perspective view of the proximal retention unit of Figure 9;

Figure 11 illustrates an exploded right perspective view of the proximal retention unit of Figure 9;

Figure 12A illustrates a side elevational view of the linear surgical stapler of Figure 6 with an anvil sheath omitted and a side portion of the cartridge channel cut away, showing the anvil engaging member in a first rotatable position when the proximal end of the anvil half is aligned with a proximal end of the cartridge half;

Figure 12B illustrates a side elevational view of the linear surgical stapler of Figure 6 with the anvil shroud omitted and a side portion of the cartridge channel cut away, showing the anvil engaging member in a second pivotal position when a proximal pin of the anvil half engages an upper surface of the anvil engaging member;

Figure 12C illustrates a side elevational view of the linear surgical stapler of Figure 6 with the anvil shroud omitted and a side portion of the cartridge channel cut away, showing the anvil engaging member after it has returned to the first pivotal position to releasably capture the proximal anvil pin and thereby engage the proximal ends of the stapler halves together;

Figure 13A illustrates a perspective view of a proximal portion of the cartridge half of the linear surgical stapler of Figure 6, showing the clamping lever in an open position;

Figure 13B illustrates a perspective view of a proximal portion of the cartridge half of Figure 13A, showing the clamping lever in a closed position in which a latch of the clamping lever engages a proximal end of the cartridge channel;

Figure 14A illustrates a perspective view of a proximal portion of the cartridge half of the linear surgical stapler of Figure 6, showing the clamping lever in the open position in which an anvil engaging element release feature is exposed through the bottom of the cartridge channel;

Figure 14B illustrates a side elevational view of proximal portions of the stapler halves of Figure 6 with the anvil shroud omitted and a side portion of the cartridge channel cut away, showing actuation of the release feature to release the proximal anvil pin from the anvil engaging member and thereby permit separation of the stapler halves;

Figure 15A illustrates a side elevational view of a proximal portion of the linear surgical stapler of Figure 6 without the wrappers and a proximal side portion of the cartridge channel outlined in dashed form, showing a firing unit of the linear surgical stapler in a proximal initial position prior to firing;

Figure 15B illustrates a side elevational view of the proximal portion of the linear surgical stapler of Figure 15A, showing the firing unit advancing distally during firing, such that a proximal end of a sliding block of the firing unit rotates the detent member in a first direction;

Figure 15C illustrates a side elevational view of the proximal portion of the linear surgical stapler of Figure 15B, showing the firing unit advancing more distally during firing such that the slide block disengages the retainer member and allows the retainer member to rotate in a second direction, such that a locking feature of the retainer member clamping lever blocks engagement of the clamping lever;

Figure 15D illustrates a side elevational view of the proximal portion of the linear surgical stapler of Figure 15C, showing the firing unit advancing proximally after firing such that the slide block re-engages and rotates the retainer member in the first direction;

Figure 15E illustrates a side elevational view of the proximal portion of the linear surgical stapler of Figure 15D, showing the firing unit returned to the proximal home position, wherein the detent member is held in a pivotal position wherein the locking feature of the clamping lever is disengaged from the clamping lever engagement;

Figure 16 illustrates a top perspective view of the firing unit of the linear surgical stapler of Figure 6, including a sliding block and a pair of rotary actuators;

Figure 17 illustrates a proximal perspective view of the sliding block and rotary actuators of the firing unit of Figure 16;

Figure 18 illustrates a top perspective view of the sliding block of the firing unit of Figure 16; Figure 19 illustrates a bottom perspective view of the rotary actuators of the firing unit of Figure 16;

Figure 20A illustrates a top cross-sectional view of the sliding block and rotary actuators of the firing unit of Figure 16, showing the actuators in a first configuration in which the first actuator is in an extended rotary position and the second actuator is in a retracted rotary position; Figure 20B illustrates a top cross-sectional view of the sliding block and actuators of the firing unit of Figure 16, showing the actuators in a second configuration in which the first actuator is retracted and the second actuator is extended;

Figure 20C illustrates a top cross-sectional view of the slide block and actuators of the firing unit of Figure 16, showing the actuators in a third configuration in which both actuators are retracted;

Figure 21 illustrates an enlarged perspective view of a proximal portion of the linear surgical stapler of Figure 6, showing a lower tab of a firing unit actuator of Figure 16 being restrained against an inner surface of the cartridge channel as the firing unit advances distally;

Figure 22 illustrates a top perspective view of another illustrative sliding block and a pair of rotary actuators, both actuators are shown in extended rotary positions;

Figure 23 illustrates a proximal perspective view of the trigger unit of Figure 22, showing the first actuator in a retracted position and the second actuator in an extended position;

Figure 24A illustrates a top perspective view of the slide block and actuators of Figure 22, showing the first actuator in a retracted position and the second actuator in an extended position;

Figure 24B illustrates a top perspective view of the trigger unit of Figure 22, showing the first actuator in an extended position and the second actuator in a retracted position;

Figure 25A illustrates a top perspective view of a proximal portion of an illustrative linear surgical stapler incorporating the slide block and actuators of Figure 22, showing the actuators in the configuration of Figure 22 in which both actuators are extended;

Figure 25B illustrates a top perspective view of the proximal portion of the linear surgical stapler of Figure 25A, showing the actuators in the configuration of Figure 24A in which the first actuator is retracted and the second actuator is extended;

Figure 25C illustrates a top perspective view of the proximal portion of the linear surgical stapler of Figure 25A, showing the actuators in the configuration of Figure 24B in which the first actuator is extended and the second actuator is retracted;

Figure 26 illustrates a top perspective view of the proximal portion of the linear surgical stapler of Figure 22, showing the firing unit advanced distally for firing with the first driver extended and the second driver retracted;

Figure 27 illustrates a top perspective view of the firing unit and a cartridge channel of the linear surgical stapler of Figure 26, showing the firing unit advanced to a distal position;

Figure 28 illustrates a top perspective view of another illustrative firing unit having a sliding block and a pair of rotary actuators, showing both actuators in extended rotary positions;

Figure 29 illustrates a top perspective view of a proximal portion of an illustrative linear surgical stapler incorporating the slide block and rotary actuators of Figure 28, showing the actuators in a configuration in which both actuators are retracted;

Figure 30 illustrates a side elevational view of a proximal portion of another exemplary linear surgical stapler according to the present invention having a cartridge half and an anvil half, with an anvil shroud and a side portion of a cartridge channel omitted;

Figure 31A illustrates a perspective side view of a sliding block and a retainer element of the linear surgical stapler of Figure 30, showing the sliding block in a proximal initial position in which the sliding block engages the retainer element;

Figure 31B illustrates a perspective side view of the slide block and retainer element of Figure 31A, showing the slide block advancing distally and causing the retainer element to rotate in a first direction;

Figure 31C illustrates a perspective side view of the slide block and retainer member of Figure 31B, showing the slide block advancing more distally to the point of disengagement and allowing the retainer member to rotate in a second direction;

Figure 31D illustrates a perspective side view of the slide block and retainer member of Figure 31C, showing the slide block advancing proximally to reengage the retainer member and cause the retainer member to rotate in the first direction;

Figure 31E illustrates a perspective side view of the slide block and retainer of Figure 31D, showing the slide block returned to the proximal initial position and the retainer after having rotated in the second direction to releasably capture the slide block;

Figure 32A illustrates a proximal perspective view of another illustrative linear surgical stapler having a cartridge half and an anvil half, not showing a retention assembly as required by the present invention, showing the clamping lever in an open position in which a release feature of the anvil half of the cartridge half is exposed for actuation to separate the stapler halves;

Figure 32B illustrates a proximal perspective view of the linear surgical stapler of Figure 32, showing the clamping lever in a closed position in which a proximal end of the clamping lever covers the anvil half release feature to prevent its actuation;

Figure 33A illustrates a proximal perspective view of another illustrative linear surgical stapler having a cartridge half and an anvil half, not showing a retention assembly as required by the present invention, showing the clamping lever in an open position in which a release feature of the anvil half of the cartridge half is exposed for actuation to separate the stapler halves;

Figure 33B illustrates a proximal perspective view of the linear surgical stapler of Figure 31, showing the clamping lever in a closed position in which a proximal end of the clamping lever covers the anvil half release feature to prevent its actuation;

Figure 34 illustrates a schematic side view of another illustrative linear surgical stapler having an actuator configured to be pulled proximally to fire the stapler;

Figure 35 illustrates a schematic side view of a composite pinion gear of the linear surgical stapler of Figure 34;

Figure 36 illustrates a schematic view of the distal end of the compound pinion gear of Figure 35; Figure 37A illustrates a top perspective view of another illustrative anvil channel and a corresponding anvil plate, showing the anvil plate aligned with a distal portion of the anvil channel during manufacturing;

Figure 37B illustrates a top perspective view of the anvil channel and anvil plate of Figure 37A, showing the anvil plate mounted in the distal portion of the anvil channel;

Figure 38 illustrates a perspective side view of the anvil channel and anvil plate of Figure 37A, showing the anvil plate secured to the anvil channel in a first illustrative manner using spot welds; and Figure 39 illustrates a perspective side view of the anvil channel and anvil plate of Figure 37A, showing the anvil plate secured to the anvil channel in a second illustrative manner using seam welds.

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be embodied in a variety of other forms, including those not necessarily illustrated in the drawings. The accompanying drawings, incorporated in and forming a part of the specification, illustrate various aspects of the present invention and, together with the description, serve to explain the principles of the invention; however, it is understood that this invention is not limited to the precise arrangements shown.

Detailed description

The following description of certain examples of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is, by way of illustration, one of the best modes contemplated for carrying out the invention. As will be understood, the invention is capable of other different and obvious aspects, all without departing from the invention as defined in the claims. Accordingly, the drawings and descriptions should be considered illustrative and not restrictive in nature.

For clarity of description, the terms “proximal” and “distal” are defined herein in relation to a surgeon or other operator grasping a surgical instrument having a distal surgical end effector. The term “proximal” refers to the position of an element disposed closest to the surgeon, and the term “distal” refers to the position of an element disposed closest to the surgical end effector of the surgical instrument and farthest from the surgeon. Furthermore, to the extent spatial terms such as “superior”, “inferior”, “vertical”, “horizontal”, or the like are used herein with reference to the drawings, it will be appreciated that such terms are used for exemplary purposes of description only and are not intended to be limiting or absolute. In that regard, it will be understood that surgical instruments such as those described herein may be used in a variety of orientations and positions not limited to those shown and described herein.

As used herein, the terms “approximately” and “around” for any numerical value or range indicate a suitable dimensional tolerance that allows the part or assembly of components to function for its intended purpose as described herein.

I. Illustrative linear surgical stapler

A. Overview of the Linear Surgical Stapler

Figures 1 and 2 show an illustrative linear surgical stapler (10) (also referred to as a “linear cutter”) suitable for use in a variety of cutting and stapling procedures, such as a gastrointestinal anastomosis procedure. The linear surgical stapler (10) includes a cartridge half (12) (also referred to as a “reload half”) and an anvil half (14) configured to releasably engage and hold tissue therebetween. The cartridge half (12) includes an elongated cartridge channel (16) having a proximal frame portion (18) slidably retaining a portion of a firing unit (34), a distal jaw portion (20) supporting a staple cartridge (80) (or “reload”), and a pair of vertical side flanges (22) disposed medially therebetween.

The cartridge half (12) further includes a clamping lever (24) pivotally coupled to a lower portion of the cartridge channel (16) in approximate alignment with the side flanges (22). The clamping lever (24) includes an elongated lever arm (26) having a free proximal end and a distal end that pivotally engages the cartridge channel (16) with a pivot pin (28). A pair of opposing jaws (30) extend distally from the distal end of the lever arm (26) adjacent the flanges (22) of the cartridge channel (16). Each jaw (30) includes a respective elongated slot (32) having a closed proximal end and an open distal end, and defining upper and lower cam surfaces configured to engage a respective engaging projection (56) of the anvil half (14). As described below, the clamping lever (24) is operable to rotate relative to the cartridge channel (16) between the open and closed positions to releasably clamp the anvil half (14) against the cartridge half (12) and thereby capture the tissue layers therebetween.

As best shown in Figure 2, the cartridge half (12) firing unit (34) includes a slide block (36) slidably retained within the proximal frame portion (18) of the cartridge channel (16), an actuator (38) (or "firing knob") movably coupled to the slide block (36), and an elongated drive beam (not shown) extending distally from the slide block (36) and configured to engage a slider (100) (see Figure 3) received within the staple cartridge (80). The actuator (38) of the present example is configured to rotate about the proximal end of the cartridge half (12) to allow "double-sided firing" of the stapler (10). Specifically, the actuator (38) may be positioned along either lateral side of the cartridge half (12) to provide distal firing travel such that the stapler (10) may be conveniently fired in a variety of orientations during a surgical procedure.

The slide block (36) is configured to be translatably biased within the proximal frame portion (18) by an actuator (38) between a proximal home position, shown in FIGS. 2 and 5A, and a distal firing position, shown in FIG. 5B. In the proximal home position, the slide block (36) abuts a post (40) secured to a proximal end of the cartridge channel (16). A free end of the post (40) supports a laterally extending pivot pin (42). As described below, the actuator (38) may be biased distally when the stapler halves (12, 14) are fully engaged together and the clamping lever (24) is closed. Distal advancement of the actuator (38) along each lateral side of the stapler (10) actuates the slide block (36) and the distally elongated drive beam, which in turn actuates the slider (100) distally through the staple cartridge (80). As described below, distal translation of the slider (100) through the staple cartridge (80) allows simultaneous stapling and cutting of tissue held between the stapler halves (12, 14).

As best shown in Figures 1 and 2, the anvil half (14) of the linear surgical stapler (10) includes an elongated anvil channel (50) having a proximal frame portion (52) and a distal jaw portion (54). The anvil channel (50) further includes an engaging feature in the form of a pair of projections (56) extending transversely from a middle portion of the anvil channel (50) toward the cartridge half (12). Each engaging projection (56) may include a circular rotatable cap configured to be caught within the slot (32) of a respective clamping lever jaw (30) when the anvil half (14) is engaged with the cartridge half (12) and the clamping lever (24) is rotated from the open position to the closed position, as described below. A pair of hooks (58) extend proximally from a proximal end of the frame portion (52) and are configured to releasably capture opposite side ends of the proximal pivot pin (42) of the cartridge half (12). The distal jaw portion (54) supports an anvil surface in the form of an anvil plate (60) having a plurality of staple-forming pockets (not shown) and further supports a distal shank member (62). In other versions of the stapler (10), the anvil surface may be integrally formed or otherwise rigidly connected to the distal jaw portion (54) of the anvil channel (50).

The anvil half (14) of the present example further includes a staple height adjustment mechanism (64) mounted to a middle portion of the anvil channel (50). The staple height adjustment mechanism (64) is operatively coupled to the anvil plate (60), for example, by one or more cam features (not shown), and includes a pair of user-engageable projections (66). Longitudinal adjustment of the projections (66) between a plurality of predetermined positions causes the anvil plate (60) to move transversely relative to the distal jaw portion (54) of the anvil channel (50). This allows adjustment of the transverse standoff distance between the anvil plate (60) and a cover (94) of the staple cartridge (80) that defines the height of the staples being formed. A larger standoff distance and therefore a larger staple height may be established when stapling thicker tissue. Conversely, a smaller standoff distance and therefore a smaller staple height may be established when stapling thinner tissue. It will be appreciated that the staple height adjustment mechanism (64) may be omitted in some embodiments, in which case the anvil surface may be fixed relative to the anvil channel (50). For example, the anvil surface may be integrally formed with or otherwise fixedly attached to the distal jaw portion (54).

As best shown in Figures 1 and 2, the linear surgical stapler (10) further includes a plurality of wrappers (70, 72, 74) that cover selected portions of the stapler (10) and promote effective gripping and manipulation of the stapler (10) by an operator during use. In the present example, the cartridge half (12) includes a first wrapper (70) that covers an outwardly facing side of the proximal frame portion (18) of the cartridge channel (16). The cartridge half (12) further includes a second wrapper (72) that covers an outwardly facing side of the clamping lever (24) and is configured to rotate with the clamping lever (24) relative to the cartridge channel (16) and the first wrapper (70). The anvil half (14) includes a third wrapper (74) covering an outwardly facing side of the proximal frame portion (52) of the anvil channel (50) including the proximal hooks (58). Each wrapper (70, 72, 74) may be coupled with its respective stapler components (10) by any suitable means apparent to those skilled in the art. Additionally, each wrapper (70, 72, 74) may be formed from one or more materials and provided with a suitable texture to promote effective gripping of the wrapper (70, 72, 74) by an operator to allow safe and efficient use of the stapler (10) during a surgical procedure.

2 and 3, the staple cartridge (80) of the present example is a unit comprising a cartridge body (82), a tray (84) covering an open bottom side of the cartridge body (82), and a plurality of staple drivers (86) received within the cartridge body (82) and each configured to drive a respective staple (88). The cartridge body (82) includes a proximal end having engaging features (90) configured to releasably engage corresponding engaging features (not shown) of the distal portion (20) of the cartridge channel jaw (16), and a distal end defining a tapered tip (92). An upper side of the cartridge body (82) defines a generally planar cover (94) through which a longitudinal slot (96) and a plurality of staple cavities (98) open. Each staple cavity (98) houses a respective staple driver (86) and a staple (88). As shown in Figure 3, the interior of the cartridge body (82) slidably houses a slider (100) comprising a slider body (102) and a blade member (104). The lateral sides of the slider body (102) support a plurality of distally tapered cam ramps (106). A proximal end of the slider body (102) includes a downwardly extending tab (108) configured to securely engage a distal end of the elongated drive beam (not shown) of the firing unit (34) when the staple cartridge (80) is mounted in the stapler cartridge half (12) 10. The blade element (104) extends upwardly from an upper side of the slide body (102) and has a distally oriented cutting edge (110) configured to cut tissue.

The slider (100) is configured to move distally through the cartridge body (82) in response to distal actuation of the firing unit (34) such that the blade element (104) moves distally through the longitudinal slot (96) to sever tissue trapped between the stapler halves (12, 14). Simultaneously, the cam ramps (106) move distally through respective interior slots (not shown) in the cartridge body (82) to urge the staple drivers (86) and staples (88) upwardly through the staple cavities (98) such that the free ends of the staples (88) pass through the fastened tissue and deform against the staple-forming pockets of the anvil plate (60). In this way, the distal actuation of the firing unit (34) allows the tissue trapped between the effector parts of the distal end of the stapler halves (12, 14) to be cut and stapled simultaneously.

The linear surgical stapler (10) and staple cartridge (80) may be further configured and operable in accordance with one or more teachings of US Patent 7,905,381; US Patent 7,954,686; US Patent 8,348,129; and/or US Patent Application 8,789,740.

B. Illustrative use of the linear surgical stapler

Figures 4A-4C show an illustrative coupling of stapler halves (12, 14) during a surgical procedure. As shown in Figure 4A, the proximal end of the anvil half (14) is aligned with the proximal end of the cartridge half (12) such that the proximal pivot pin (42) of the cartridge half (12) is received by the proximal hooks (58) of the anvil half (14). With the clamping lever (24) in the open position, the anvil half (14) is then rotated toward the cartridge half (12) about the proximal pivot pin (42) to direct the engaging projections of the anvil half (14) into the slots (32) of the clamping lever jaws (30). Once the jaws (30) of the clamping lever receive the engaging projections (56), the clamping lever (24) rotates to the partially closed position shown in Figure 4B. In this partially closed position of the clamping lever (24), the anvil half (14) is partially clamped by the cartridge half (12) such that the stapler (10) may now be held in a single hand without the halves (12, 14) undesirably separating from one another. Furthermore, in this state, the distal portions of the stapler halves (12, 14) remain spaced apart from one another to allow placement of tissue between the distal portions. It will be appreciated that tissue may be placed between the distal portions of the stapler halves (12, 14) before or after this partially clamped state is achieved.

As shown in Figure 4C, the clamping lever (24) is then further rotated toward its fully closed position such that the cam surfaces of the clamping lever jaws (30) draw the engaging projections of the anvil half (14) proximally against the closed proximal ends of the slots (32) of the clamping lever jaws (30), thereby completely clamping the stapler halves (12, 14) together with the tissue securely positioned therebetween. Once the stapler halves (12, 14) of the stapler (10) are fully clamped, the actuator (38) may be manipulated to fire the staple cartridge (80). In particular, as shown in Figures 5A and 5B, the actuator (38) rotates about the proximal end of the stapler (10) to cover one of the lateral sides of the stapler (10). The actuator (38) is then actuated distally to actuate the firing unit (34) in the manner described above and thereby simultaneously cut and staple the clamped tissue. Upon completion of a distal firing stroke, the actuator (38) may return to its proximal home position shown in FIG. 2, and the clamping lever (24) may then be opened to separate the stapler halves (12, 14) from one another and release the stapled and cut tissue.

II. Illustrative linear surgical stapler having a proximal retention unit

As described above in connection with Figures 4A-4C, the clamping lever (24) must be actuated from its fully open position to at least a partially closed position in which the lever jaws (30) initially capture the engaging projections (56) of the anvil half (14) to prevent separation of the anvil half (14) from the cartridge half (12). However, this initial engagement process requires the use of both hands by the operator, which prevents the operator from being able to mount tissue onto the stapler (10) when the clamping lever (24) is fully open. Because it is generally easier to assemble the tissue into the stapler halves (12, 14) while the clamping lever (24) is fully open, thereby allowing the distal portions of the stapler halves (12, 14) to be further apart from each other, the operator often requests the assistance of an assistant in a “4-handed” unit approach.

In many instances, it may be desirable for an operator to be able to assemble tissue onto the separate halves of a linear surgical stapler with the clamping lever in a fully open position and without the aid of an assistant, such that the operator can use a first hand to hold the stapler and a second hand to position the tissue relative to the stapler. The illustrative stapler 200 described below includes features that allow the proximal ends of the first and second stapler halves to remain engaged with each other while the clamping lever is in a fully open position. This configuration allows the operator to conveniently manipulate the stapler 200 with a first hand, while leaving the other hand free to manipulate the tissue relative to the stapler 200.

A. Overview of the Linear Surgical Stapler

Figures 6 and 7 show another illustrative linear surgical stapler (200) (or “linear cutter”) that is generally similar to the linear surgical stapler (10) described above, except as otherwise described below. The linear surgical stapler (200) includes a cartridge half (202) (or “reload half”) and an anvil half (204) configured to releasably engage and clamp tissue therebetween to simultaneously cut and staple the clamped tissue.

The cartridge half (202) includes an elongated cartridge channel (206) having a proximal frame portion (208) and a distal jaw portion (210). The proximal frame portion (208) slidably retains a firing unit (350) and includes a pair of laterally opposed vertical side flanges (212). Each side flange (212) includes a vertical slot (214) disposed at a distal end thereof, and a tapered notch (216) disposed at a proximal end thereof. An outwardly projecting reinforcing rib (218) extends longitudinally between the distal slot (214) and the proximal notch (216) of each side flange (212) and is configured to provide the side flange (212) with enhanced rigidity. An outwardly flared upper segment (220) defines an upper edge of a proximal portion of each side flange (212) and is configured to facilitate reception of the anvil half (204) by the cartridge half (202), as described in greater detail below. Each side flange (212) further includes an elongated firing slot (222) extending longitudinally between the proximal notch (216) and the distal slot (214) along a bottom side of the side flange (212). The elongated firing slots (222) are configured to guide the firing unit (350) between proximal and distal positions. The firing unit (350) is described in greater detail below in connection with FIGS. 16-21.

The distal portion 210 of the cartridge channel jaw 206 is configured to receive a staple cartridge 230 (or “reload”), which may be similar to the staple cartridge 80 described above, except as otherwise described below. The staple cartridge 230 includes a cartridge body 232 that houses a plurality of staple drivers and staples (not shown) similar to the staple drivers 86 and staples 88. The cartridge body 232 further includes a longitudinal slot 234 configured to slidably receive a blade element 366 (see FIG. 16) of the firing unit 350, and a pair of inner slots (not shown) configured to slidably receive a pair of cam ramps 360 (see FIG. 16) of the firing unit 350. In other embodiments, the staple cartridge 230 and firing unit 350 may alternatively be configured such that the blade element 366 and cam ramps 360 are received within the cartridge body 232, similar to the staple cartridge 80. The staple cartridge 230 of the present embodiment further includes a pair of proximal engaging legs 236 configured to pass through an opening (not shown) in a bottom wall of the cartridge channel 206 and releasably engage a clamping lever pivot pin 242 with a snap-fit engagement.

The cartridge half (202) further includes a clamping lever (240) pivotally coupled to the cartridge channel (206) with a clamping lever pivot pin (242) disposed in approximate alignment with distal slots (214) of the cartridge channel side flanges (212). The clamping lever (240) includes an elongated lever arm (244) having a free proximal end (246) and a distal end that pivotally couples to a bottom of the cartridge channel (206) with a pivot pin (242). A pair of opposed jaws (248) extend distally from the distal end of the lever arm (244) along the cartridge channel side flanges (212). Each jaw (248) includes a curved slot (250) having a closed proximal end and an open distal end configured to receive an engaging projection of the anvil half (204), as described below.

The clamping lever (240) is operable to rotate relative to the cartridge channel (206) between an open position wherein the proximal end (246) of the lever arm (244) is spaced from the cartridge channel frame portion (208), and a closed position wherein the proximal end (246) faces the cartridge channel frame portion (208). Actuation of the clamping lever (240) from the open position to the closed position serves to clamp the anvil half (204) against the cartridge half (202). In particular, the curvature of each jaw slot (250) defines respective upper and lower cam surfaces configured to engage and draw the respective engaging projection of the anvil half (204) toward the cartridge channel (206) when the clamping lever (240) is rotatably closed, as described below.

The cartridge half (202) of the present example further includes a resilient member shown in the form of a flat spring (252) biasing the lever arm (244) toward the open position. Accordingly, the flat spring (252) promotes disengagement of the lever jaws (248) from the anvil half (204) upon initial advancement of the clamping lever (240) from the closed position toward the open position. The cartridge half (202) further includes a clamping lever engaging member (254) disposed at the proximal end (246) of the lever arm (244). As described in more detail below, the clamping lever engaging member (254) flexibly biases to engage a proximal end of the cartridge channel (206) and thereby releasably retain the clamping lever (240) in the closed position, for example, while firing the stapler (200).

The anvil half (204) of the linear surgical stapler (200) includes an elongated anvil channel (260) having a proximal frame portion (262) and a distal jaw portion (264). The proximal frame portion (262) includes a pair of laterally opposed vertical side flanges (266) that are configured to be received between the cartridge channel side flanges (212) when the anvil half (204) is mated with the cartridge half (202). A distal pin-like distal engagement projection (268) extends laterally through the distal ends of the anvil channel side flanges (266), and a proximal pin-like proximal pivot projection (270) extends laterally through the proximal ends of the anvil channel side flanges (266). The anvil pins (268, 270) are configured to facilitate engagement of the anvil half (204) with the cartridge half (202), as described below.

The distal jaw portion (264) of the anvil half (204) supports an anvil surface (272) having a plurality of staple-forming pockets (not shown) configured to deform staple legs ejected by the staple cartridge (230) when the stapler (200) is fired. In some embodiments, the anvil surface (272) may be integrally formed or otherwise rigidly connected to the distal jaw portion (264), for example, as described below in connection with FIGS. 37A-39. In other embodiments, the anvil surface (272) may be fitted relative to the distal jaw portion (264) in a manner similar to the anvil plate (60) of the stapler (10) described above. The distal portion (264) of the anvil half jaw (204) additionally supports a distal conical shank element (274).

Similar to the linear surgical stapler (10), the linear surgical stapler (200) includes a plurality of wraps (256, 276) that cover selected portions of the stapler (200) and promote efficient gripping and manipulation of the stapler (200) by an operator during use. In particular, a clamping lever wrap (256) is attached to and covers an outwardly facing side of the clamping lever (240), such that the clamping lever wrap (256) is configured to rotate with the clamping lever (240) relative to the cartridge channel (206). Additionally, an anvil wrap (276) is attached to and covers an outwardly facing side of the anvil channel (260). In some embodiments, the anvil sheath (276) may be coupled with the anvil channel (260) in accordance with the teachings of US patent application US-2020/0046353 A1, entitled “Clamping Assembly for Linear Surgical Stapler”. It will be appreciated that in other embodiments, the sheaths (256, 276) may be coupled to the clamping lever (240) and the anvil channel (260) in a variety of other ways readily apparent to those skilled in the art.

During assembly of the stapler halves (202, 204), the proximal pin (270) of the anvil half (204) is directed toward the proximal tapered notches (216) of the cartridge channel (206). Meanwhile, the jaw lever (240) is held in the open position by the resilient member (252) such that the open distal ends of the curved jaw slots (250) align with the open upper ends of the distal slots (214) of the cartridge channel. The anvil half (204) is then rotated about the proximal pin (270) to drive the distal pin (268) of the anvil half (204) into the vertical distal slots (214) of the cartridge channel (206) and the curved jaw slots (250) of the clamping lever (240). The clamping lever (240) is then rotated from the open position to the closed position, causing the upper and lower cam surfaces of the curved jaw slots (250) to engage and draw the distal pin (268) into the closed proximal ends of the curved jaw slots (250). This action draws the distal portion (264) of the anvil channel jaw (260) toward the distal portion (210) of the cartridge channel jaw (206), thereby gripping any tissue positioned between the anvil surface (272) and the staple cartridge (230). When the clamping lever (240) reaches the fully closed position, the clamping lever engaging member (254) engages the proximal end of the cartridge channel (206) to maintain the clamping lever (240) in the closed position. The stapler (200) may then be fired by actuating the firing unit (350) distally similar to the firing unit (34). After firing, the firing unit (350) returns to its proximal initial position and the clamping lever engagement element (254) disengages from the cartridge channel (206) to allow opening of the clamping lever (240) and subsequent separation of the stapler halves (202, 204).

B. Proximal retention unit of the linear surgical stapler

Figures 8-11 show details of an exemplary retention unit 300 disposed at a proximal end of the linear surgical stapler 200 and configured to releasably retain portions of the anvil half 204 and the firing unit 350, as described below. The retention unit 300 of the present example includes an anvil engaging member 302 and a retainer member 304, both of which are pivotally coupled to a proximal end of the cartridge channel 206 by a laterally extending pin 306 disposed proximally of the firing slots 222.

As best shown in Figures 10 and 11, the anvil engagement member (302) includes a center body (308), an engagement finger (310) extending upwardly from an upper side of the center body (308), a release button (312) extending downwardly from a lower side center body (308), and a stop tab (314) disposed on an outwardly facing lateral side of the center body (308) opposite the detent member (304). An upper end of the engagement finger (310) tapers distally and defines an upper cam ramp (316) configured to engage the proximal pin (270) of the anvil half (204) in the manner described below. The anvil engaging member (302) further includes a central cutout feature (318) shaped to receive a portion of the retainer member (304), as described below, and an opening (320) extending laterally through the central body (308).

The retainer member (304) includes a generally cylindrical central body (322), a distal finger (324) extending distally from a distal side of the central body (322), a hook member (326) extending proximally from a proximal side of the central body (322), and a stop tab (328) disposed on an outwardly facing lateral side of the central body (322) opposite the anvil engaging member (302). As shown in Figure 11, a lateral side of the retainer member (304) facing the anvil engaging member (302) includes an annular recess (330) and a stem (332) extending laterally from the annular recess (330) toward the anvil engaging member (302). The distal finger (324) of the retainer element (304) includes a proximal upper cut feature (334) defining a proximal cam ramp of the distal finger (324), and a slanted distal end defining a distal cam ramp of the distal finger (324). These proximal and distal cam ramps of the distal finger (324) are configured to interact with the trigger unit (350) as described in greater detail below.

The anvil engaging member (302) and the retainer member (304) are configured to be joined together such that their inwardly facing lateral sides face each other along a plane extending generally parallel to the longitudinal axis of the linear surgical stapler (200). The central body (322) of the retainer member (304) is received within the central cutout feature (318) of the anvil engaging member (302) such that the engaging finger (310) and the release button (312) of the anvil engaging member (302) laterally overlap the central body (322) of the retainer member (304). Additionally, the side stem (332) of the retainer member (304) is received through the side opening (320) of the anvil retainer member (302) such that the anvil engaging member (302) is rotatable about the stem (332). The pin (306) is then received through a central bore of the side stem (332) and secured at its lateral ends to the side flanges (212) of the cartridge channel as shown in FIGS. 8 and 9. Accordingly, the anvil engaging member (302) and the retainer member (304) are coaxially disposed about a lateral axis defined by the pin (306) and the stem (332). As described below, the anvil engaging member (302) and the retainer member (304) are configured to rotate independently of and relative to each other about the shared axis.

The retaining unit (300) further includes a resilient member shown in the form of a torsion spring (340) positioned between the anvil engaging member (302) and the retainer member (304). A first lateral side of the torsion spring (340) and a corresponding first spring leg (342) are captured within a complementary shaped recess (321) formed in the central body (308) of the anvil engaging member (302). A second lateral side of the torsion spring (340) is received within the annular recess (330) of the retainer member (304) such that a corresponding second spring leg (344) is captured within a radially extending slot (336) formed in the central body (322) of the retainer member (304). The torsion spring (340) is configured to flexibly bias the anvil engaging member (302) and the retainer member in opposite rotational directions about the lateral axis defined by the pin (306). In particular, in the views illustrated in Figures 9 and 12A-12C, the torsion spring (340) is configured to bias the anvil engaging member (302) in a counterclockwise direction about the pin (306), such that the engaging finger (310) is biased distally. Additionally, the torsion spring (340) is configured to bias the retainer member (304) in a clockwise direction, such that the distal finger (324) is biased upwardly and the proximal hook member (326) is biased downwardly.

As shown in Figure 9, the stop tab (314) of the anvil engagement member (302) is configured to abut the upper surface of an adjacent first stop notch (224) formed at the distal end of a corresponding first side flange (212) of the cartridge channel (206). Additionally, the stop tab (328) of the retainer member (304) is configured to abut the lower surface of an adjacent second stop notch (226) formed at the distal end of a corresponding second side flange (212) of the cartridge channel (206). The anvil engaging member stop tab (314) and its respective channel stop notch (224) are configured to interact such that the anvil engaging member (302) is biased into a rotational orientation wherein the engagement finger (310) extends generally vertically. Additionally, the detent member stop tab (328) and its respective channel stop notch (226) are configured to interact such that the detent member (304) is biased into a rotational orientation wherein the distal finger (324) and proximal hook member (326) extend generally horizontally.

Figures 12A-12C show the anvil engaging member (302) with the proximal pin (270) of the anvil half (204) to provide releasable engagement of the proximal end of the anvil half (204) with the proximal end of the cartridge half (202). Figure 12A shows the cartridge half (202) and the anvil half (204) in a pre-assembled state in which the anvil half (204) is separated from the cartridge half (202), the clamping lever (240) (not shown) is in a fully open position, and the firing unit (350) is held in a proximal home position by the distal finger (324) of the detent member (304), as described in more detail below. As shown in Figures 12A and 12B, the proximal end of the anvil half (204) is aligned and drawn toward the proximal end of the cartridge half (202) such that the proximal pin (270) is drawn into the proximal tapered notches (216) of the cartridge channel (206) and contacts the upper cam ramp (316) of the anvil engaging member (302). This engagement biases the anvil engaging member (302) to rotate in a clockwise direction such that the engaging finger (310) moves proximally, allowing the proximal pin (270) to slide over the tapered distal pin of the engaging finger (310). As shown in Figure 12C, the anvil engaging member (302) is then adjusted rearwardly in a counterclockwise direction such that the engaging finger (310) engages and captures the proximal pin (270), thereby coupling the proximal end of the anvil half (204) with the proximal end of the cartridge half (202). Because the anvil engaging member (302) is rotatable independently of the retainer member (304), the retainer member (304) remains rotationally fixed throughout the coupling steps shown in Figures 12A-12C.

As shown in Figures 13A and 13B, the release button (312) of the anvil engagement member (302) is exposed and accessible to an operator only when the clamping lever (240) is in the open position. As shown in Figure 13A, the release button (312) extends through an opening formed in a bottom wall (228) of the cartridge channel (206). As shown in Figure 13B, the clamping lever (240) in the closed position conceals and blocks access to the release button (312), thereby preventing inadvertent actuation of the release button (312) and subsequent separation of the proximal ends of the stapler halves (202, 204) during or immediately prior to a firing stroke. As shown in Figures 14A and 14B, separation of the proximal ends of the stapler halves (202, 204) is accomplished by opening the clamping lever (240) and actuating the release button (312) distally. As shown in Figure 14B, this causes the anvil engaging member (302) to rotate in a clockwise direction, thereby moving the engaging finger (310) proximally to release the proximal pin (270) from the anvil half (204) so that the anvil half (204) can be separated from the cartridge half (202).

As shown in Figures 15A-15E, a sliding block (352) of the firing unit (350) is configured to releasably fit into the detent member (304) of the retention unit (300) to provide an operator with a tactile indication of when the firing unit (350) is in a proximal initial unit, as described below. Referring briefly to Figure 18, the sliding block (352) includes a block body (370) that is slidably received between the side flanges (212) of the cartridge channel (206), and a finger (372) that extends proximally from a proximal end of the block body (370). The block finger (372) has a rounded proximal end defining a proximal cam ramp of the block finger (372) and a cutting feature (374) defining a distal cam ramp of the block finger (372).

Figure 15A shows the firing unit (350) in a proximal initial position in which the sliding block (352) is disposed proximally within the cartridge channel (206). In this proximal position, the block finger (372) engages and interlocks with the detent finger (324) such that the proximal cam ramp (324) of the detent finger comes into contact with the distal cam ramp of the block finger (372). This interaction between the block finger (372) and the detent finger (324) slightly urges the detent element (304) in a counterclockwise direction (in the view of Figure 15A), against the bias of the torsion spring (340), such that the detent stop tab (328) is slightly spaced from the lower surface of the channel stop notch (226) of the respective cartridge. In response, the torsion spring (340) biases the detent member (304) in a clockwise direction so that the detent finger (324) exerts an upwardly directed force on the block finger (372). This exertion of forces provides a detent engagement which releasably retains the trigger unit (350), via a sliding block (352), in the proximal home position.

As shown in Figure 15B, when the firing unit (350) is actuated distally by an operator performing a firing stroke, the blocking finger (372) urges the detent finger (324) downward such that the detent member (304) rotates in a counterclockwise direction. As shown in Figure 15C, as the firing unit (350) advances more distally, the blocking finger (372) disengages the detent finger (324) and the bias of the torsion spring (340) rotates the detent member (304) in a clockwise direction such that the detent stop tab (328) abuts the lower surface of the stop notch (226) in the respective cartridge channel. When the retainer member (304) assumes this pivotal position, the proximal hook member (326) of the retainer member (304) engages an upper pin (255) of the clamping lever engaging member (254), thereby preventing the clamping lever engaging member (254) from being actuated to release the clamping lever (240) from the cartridge channel (206). Accordingly, the hook member (326) functions as a safety locking feature that prevents the clamping lever (240) from being opened unless the firing unit (350) is in the proximal home position. Advantageously, this feature ensures that the stapler halves (202, 204) cannot be separated from each other while a blade element (366) (see Figure 16) of the stapler (200) is exposed through a top cover of the staple cartridge (230) during a firing stroke.

As shown in Figures 15D and 15E, after the stapler 200 has been fired, the firing unit 350 returns to its proximal home position within the cartridge channel 206. As the firing unit 350 advances proximally, the proximal cam ramp of the blocking finger 372 engages the distal cam ramp of the detent finger 324, thereby urging the detent finger 324 downwardly and rotating the detent member 304 in a counterclockwise direction against the bias of the torsion spring 340. When the firing unit (350) reaches the proximal home position shown in Figure 15E, the blocking finger (372) seats within the upper cutting feature (334) of the detent finger (324) and the blocking finger (372) holds the detent member (304) in a slightly counterclockwise position such that the proximal hook member (326) no longer obstructs the upper pin (255) of the clamping lever engaging member (254). Accordingly, the clamping lever engaging member (254) may be actuated to disengage the cartridge channel (206) and permit opening of the clamping lever (240) to separate the stapler halves (202, 204). It will be appreciated that the detent interaction between the detent element (304) and the slide block (352), as described above, provides the operator with a tactile indication of when the firing unit (350) separates and returns to its proximal initial position, thereby indicating to the operator when it is safe to open the clamping lever (240) and separate the stapler halves (202, 204).

C. Linear surgical stapler firing unit

Figures 16-21 show additional details of the firing unit (350) of the linear surgical stapler (200). As best shown in Figure 16, the firing unit (350) of the present example includes a slide block (352), a pair of actuators (354, 356) (or “firing knobs”) rotatably coupled to the slide block (352), and a plurality of elongated beams (358, 360) extending distally from the slide block (352). A pair of side beams (358) are coupled at their proximal ends to a distal end of the slide block (352) and terminate distally in a pair of cam ramps (360). The cam ramps (360) are configured to actuate staple drivers (not shown) housed within the staple cartridge (230) to fire staples (not shown) from the cartridge (230), in a manner similar to the cam ramps (106) of the slider (100) described above. A center beam (362) engages the side beams (358) via a bridge member (364) distally spaced from the slide block (352). The center beam (362) terminates distally in an angled blade member (366) having a distal cutting edge (368) configured to sever tissue clamped between the distal portions of the stapler halves (202, 204). The firing unit (350) is distally actuatable through the cartridge channel (206) to simultaneously cut and staple tissue held between the stapler halves (202, 204) in response to an operator distally pushing one of the exposed actuators (354, 356), as described below.

As best shown in Figures 17-19, the actuators (354, 356) are rotatably coupled to the sliding block body (370) with a pivot pin (376), such that each actuator (354, 356) extends outwardly from a respective lateral side of the block body (370) and is configured to rotate through a side opening (378) formed in the block body (370). Each actuator (354, 356) includes an actuator body (380) and a paddle (382) extending transversely from an outer end of the actuator body (380), such that the actuator bodies (380) are generally horizontal and the paddles (382) are generally vertical in the orientations illustrated therein. As shown in Figure 19, each actuator body (380) includes a wedge feature (384) at its inner end that is configured to move through the side opening (378) of the block body (370). The wedge features (384) are configured to abut each other such that each actuator (354, 356) is automatically configured to rotatably retract relative to the sliding block (352) when an operator rotatably exposes the opposite actuator (354, 356), as described in greater detail below in connection with Figures 20A and 20B.

As best seen in Figures 17 and 19, each actuator body (380) further includes a detent projection (386) and a stop tab (388) projecting downwardly from a bottom surface of the actuator body (380). Each detent projection (386) is configured to slidably engage a respective detent slot (375) formed in the proximal portion of a respective lateral side of the slide block body (370). Each stop tab (388) is configured to be received within a recess (379) formed in the distal portion of a respective lateral side of the slide block body (370). As each actuator (354, 356) rotates between a retracted rotational position and an exposed rotational position, its detent projection (386) slides longitudinally within the respective detent slot (375). Additionally, when an actuator (354, 356) rotates from its exposed rotational position to its retracted rotational position, its stop tab (388) is received and bears within the inner side wall of the respective recess (379).

The actuators (354, 356) of the linear surgical stapler (200) are configured to allow firing from both sides of the stapler (200), such that the stapler (200) can be fired by actuating an actuator (354, 356) distally along each lateral side of the stapler (200). The actuators (354, 356) are further configured such that at least one actuator (354, 356) remains retracted at all times to prevent an unused actuator (354, 356) from interfering with the operator's ability to securely grip the stapler (200) with a support hand while firing the stapler (200) with a firing hand. As described below, each actuator (354, 356) of the present version can rotate relative to the sliding block (352) approximately 90 degrees between a retracted rotational position and an exposed rotational position.

Figure 20A shows the first actuator (354) in an exposed rotational position in which its paddle (382) is distally oriented and extends transversely to a longitudinal axis of the firing unit (350), and the second actuator (356) in a retracted rotational position in which its paddle (382) is proximally oriented and extends parallel to the longitudinal axis. In this configuration, an operator can grasp, with a first hand, the second lateral side of the stapler (200) along which the paddle (382) of the second actuator (356) is retracted, and simultaneously drive the exposed paddle (382) of the first actuator (354) distally with a second hand to perform a firing movement.

Figure 20B shows the actuators (354, 356) in an opposite orientation achieved by urging the paddle (382) of the retracted second actuator (356) to distally rotate the second actuator body (380) about the pin (376) such that the wedge feature (384) of the second actuator (356) is driven against the wedge feature (384) of the first actuator (354). This interaction causes the first actuator (354) to automatically rotate from an exposed rotational position to a retracted rotational position, shown in Figure 20B. In this configuration, the operator grasps, with a first hand, the first lateral side of the stapler (200) along which the paddle (382) of the first actuator (354) is retracted, and simultaneously with a second hand, urging the exposed paddle (382) of the second actuator (356) distally to perform a firing movement. It will be appreciated that the second actuator (356) may also automatically rotate from its exposed rotational position to its retracted rotational position in response to rotation of the first actuator (354).

Figure 20C shows both actuators (354, 356) in retracted rotational positions in which both paddles (382) are proximally oriented such that they extend generally parallel to the longitudinal axis of the firing unit (350). Such a configuration may provide the surgical stapler (200) with a compact profile suitable for packaging of the device and other storage or transportation purposes, for example.

As shown in Figures 7 and 21, the proximal portion of each longitudinal firing slot (222) of the cartridge channel (206) is shaped to allow the respective actuator (354, 356) to rotate between its retracted and exposed positions while the firing unit (350) is in its proximal home position. Once the firing unit (350) is actuated distally during a firing stroke, the firing slots (222) prevent the actuators (354, 356) from rotating until the firing unit (350) returns to its proximal home position after the firing stroke is complete. For example, Figure 21 shows the first driver (354) in an exposed position and being distally urged through a respective longitudinal firing slot (222) such that its stop tab (388) and subsequently its detent projection (386) are captured between the slide block body (370) and a facing inner surface of the respective side flange (212) of the cartridge channel (206). Accordingly, the stop tab (388) and the detent projection (386) of the first driver (354) are restrained to prevent inadvertent rotation of the first driver (354) from its exposed position to its retracted position while the stapler (200) is fired. It will be understood that the second actuator (356) is similarly restrained by the slide block body (370) and the adjacent side flange (212) of the cartridge channel when the second actuator (356) is in the exposed position and is distally actuated to fire the stapler (200).

III. Illustrative Alternative Sliding Blocks and Actuator Units

In some instances, it may be desirable to provide a linear surgical stapler (200) with rotary actuators that are configured to be simultaneously oriented in exposed rotary positions, unlike the actuators (354, 356) described above. Illustrative alternative actuators (402, 404, 432, 434) described below demonstrate such functionality.

Figures 22 and 23 show another illustrative slide block (400) and pair of actuators (402, 404) (or “firing knobs”) suitable for use with a linear surgical stapler (200). The slide block (400) and actuators (402, 404) are similar to the slide block (352) and actuators (354, 356) described above in that the actuators (402, 404) are pivotally coupled to the slide block (400) about a shared vertical pivot axis defined by a pivot pin (405). Additionally, each actuator (402, 404) is rotatable approximately 90 degrees between an exposed pivotal position and a retracted pivotal position to provide double-sided firing. Each actuator (402, 404) includes a generally triangular actuator body (406) having an inner end that rotatably engages the slide block (400) and an outer end from which a paddle (408) extends transversely. Although not shown, the slide block (400) and actuators (402, 404) may include detent features that provide an operator with a tactile indication of the rotational position of each actuator (402, 404). In some embodiments, such detent features may be similar to those of the slide block (352) and actuators (354, 356) described above. In some embodiments, such detent features may be supplemented or replaced by other suitable friction-inducing elements, such as O-rings, to enhance the tactile feel to the operator.

As best shown in Figures 22 and 23, the inner end of each actuator body (406) includes a plurality of laterally extending barbed arms (410) configured to overlap and mate with similar barbed arms (410) of the opposite actuator body (406). The barbed arms (410) of each actuator (402, 404) are configured such that when a given actuator (402, 404) rotates from an exposed rotational position to a retracted rotational position, its barbed arms (410) engage the outer end of the opposite actuator body (406) and automatically rotate the opposite actuator (402, 404) from a retracted position to an extended position. In other words, in the present example, each actuator (402, 404) is configured to rotatably drive the opposite actuator (402, 404) when the actuators (402, 404) are rotatably displaced from each other by 90 degrees.

Figure 24A shows the actuators (402, 404) in an illustrative configuration where the first actuator (402) is retracted and the second actuator (404) is extended. Figure 24B shows the actuators (402, 404) in an opposite configuration where the first actuator (402) is extended and the second actuator (404) is retracted, which can be achieved from the configuration shown in Figure 24A by simply rotating the second actuator (404) from its extended position to its retracted position. Figure 25A shows the proximal end of an illustrative linear surgical stapler (420) incorporating a slide block (400) and drivers (402, 404), showing the slide block (400) in a proximal home position with both drivers (402, 404) extended, similar to Figure 22. Figure 25B shows the proximal end of the stapler (420) with the slide block (400) in the proximal home position with the first driver (402) retracted and the second driver (404) extended, similar to Figure 24A. Figure 25C shows the proximal end of the stapler (420) with the slide block (400) in the proximal home position with the first driver (402) extended and the second driver (404) retracted, similar to Figure 24B.

Figure 26 shows the first driver (402) in the extended rotational position and in a distal longitudinal position after being distally translated with the slide block (400) to fire the stapler (420). As best shown in Figures 22, 23 and 27, each driver (402, 404) includes a pair of vertically extending projections (414) disposed at an outer end of the driver body (406). The vertical projections (412) of each driver (402, 404) are configured to move longitudinally within a respective guide channel (426) defined between facing lateral sides of a cartridge channel (422) and a cartridge shell half (424) when the slide block (400) and the drivers (402, 404) are actuated distally. This tracking of the vertical projections (412) within the guide channels (426) prevents unintentional rotation of the actuators (402, 404) during a firing stroke. As the projections (412) of the first actuator (402) demonstrate in Figure 27, the projections (412) are aligned parallel to the longitudinal axis of the cartridge channel (422) when the respective actuator (402, 404) is in the exposed rotational position, such that both projections (412) are captured and move within the guide channel (426). As the projections (412) of the second actuator (404) demonstrate in Figure 27, only one of the projections (412) of an actuator (402, 404) moves within the respective guide channel (426) when an actuator (402, 404) is in the retracted rotational position.

Figure 28 shows another illustrative slide block (430) and a corresponding pair of rotary actuators (432, 434) suitable for use with a linear surgical stapler (200). The slide block (430) and actuators (432, 434) are similar to the slide block (400) and actuators (402, 404) described above, except that each actuator (432, 434) has a rounded inner end (436) which omits the pointed arms (410). Accordingly, rotation of one actuator (432, 434) from its extended rotary position to its retracted rotary position while the opposite actuator (432, 434) is retracted does not operate to automatically extend the opposite actuator (432, 434). Accordingly, unlike the actuators (402, 404), the actuators (432, 434) are configured to simultaneously assume a retracted rotary position, as exemplified by the linear surgical stapler (438) shown in Figure 29.

IV. Illustrative Reciprocating Retainer Element and Sliding Block Assembly

In some instances, it may be desirable to configure the firing unit of a linear surgical stapler to include a sliding block that omits proximally extending projections, as opposed to the sliding block 352 of the firing unit 350 described above. The illustrative alternative linear surgical stapler 440 described below includes a firing unit that is so configured.

Figures 30 and 31A-31E show the proximal portion of another illustrative linear surgical stapler (440) having a cartridge half (442) and an anvil half (444) configured to releasably engage one another to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. The stapler (440) may be generally similar to the stapler (200) described above, except as otherwise described below. The cartridge half (442) includes an elongated cartridge channel (446) and a clamping lever (448) coupled to the cartridge channel (446) and configured to pivot between open and closed positions to clamp the stapler halves (442, 444) together. The cartridge half (442) further includes, among other features, a firing unit (450) and a proximal retention unit (452) supported by a proximal frame portion of the cartridge channel (446). The anvil half (444) includes, among other features, an elongated anvil channel (454) and a proximal pin (456) coupled to a proximal end of the anvil channel (454) and configured to engage by the proximal retention unit (452) of the cartridge half (442), as described below.

The firing unit (450) of the linear surgical stapler (440) is similar to the firing unit (350) of the stapler (200) in that the firing unit (450) includes a slide block (460) and a pair of rotary actuators (462) coupled with the slide block (460), with only one actuator (462) being shown in Figure 30. Like the actuators (354, 356), each actuator (462) is rotatable relative to the slide block (460) between a retracted rotational position and an exposed rotational position. A proximal end of the slide block (460) includes an upwardly extending finger (464) having rounded proximal and distal ends defining respective proximal and distal cam ramps configured to releasably engage the proximal retention unit (452), as described below.

The retention unit (452) of the linear surgical stapler (440) is similar to the retention unit (300) of the stapler (200) in that the retention unit (452) includes an anvil engaging member (466) configured to releasably engage a proximal end of the cartridge half (442) with a proximal end of the anvil half (444), and a detent member (468) configured to releasably retain the firing unit (450) in a proximal home position. The anvil engaging member (466) and the detent member (468) are pivotally coupled to a proximal end of the cartridge channel (446) about a shared axis of rotation defined by a laterally extending pivot pin (470). Additionally, the anvil engaging member (466) and the retainer member (468) are flexibly biased in opposite rotational directions by a flexible member (not shown) similar to the torsion spring (340). In particular, in the view shown in Figure 30, the retainer member (468) is biased in a counterclockwise direction and the anvil engaging member (466) is biased in a clockwise direction. The anvil engaging member (466) includes an engaging feature (not shown), which may be similar to the engaging finger (310) of the anvil engaging member (302), configured to releasably capture the proximal pin (456) of the anvil half (444) to couple the anvil half (444) with the cartridge half (442). The anvil engaging member (466) further includes a proximally extending release button (472) configured to selectively disengage the proximal pin engaging feature (456) to allow separation of the stapler halves (442, 444). The detent member (468) includes a distally extending finger (474) having a distal pin tapering downwardly to define opposing proximal and distal cam ramps configured to engage the sliding block finger (464), as described below.

Figures 31A-31E show the interactions between the slide block (460) and the detent member (468) during firing of the linear surgical stapler (440). Figure 31A shows the slide block (460) in a proximal initial position in which the detent finger (474) overlaps an upper end of the slide block finger (464). When the slide block (460) is driven distally during a firing travel, the proximal rounded end of the slide block finger (464) distally pushes the proximal cam ramp of the detent finger (474), thereby causing the detent member (468) to rotate such that the detent finger (474) moves upwardly, as shown in Figure 31B. As the sliding block (460) advances more distally, the detent finger (474) disengages the sliding block finger (464) and the detent member (468) returns to its original rotational position, as shown in Figure 31C. As shown in Figures 31D and 31E, when the sliding block (460) is retracted proximally after firing the stapler (440), the rounded proximal end of the sliding block finger (464) engages the distal cam surface of the detent finger (474). This causes the detent member (468) to rotate such that the detent finger (474) moves upwardly and receives the sliding block finger (464) once again as the sliding block (460) returns to the initial proximal position shown in Figure 31E. Advantageously, the detent interaction described above between the detent finger (474) and the sliding block finger (464) provides the operator with a tactile indication of when the firing unit (450) advances distally and returns proximally to its proximal home position.

V. Illustrative linear surgical staplers having concealable anvil release features

As described above, the linear surgical stapler 200 includes a first releasable engaging feature in the form of an anvil engaging member 302 that releasably couples the proximal end of the anvil half 204 to the proximal end of the cartridge half 202. The stapler 200 further includes a second releasable engaging feature in the form of a clamping lever engaging member 254 that releasably holds the clamping lever 240 in the closed position. The cartridge half (202) is configured such that the anvil engaging member (302) release button (312) is concealed by the clamping lever (240) while the clamping lever (240) is in the closed position, thereby preventing unwanted confusion for the operator between the anvil release button (312) and the clamping lever engaging member (254) during a surgical procedure. Illustrative linear surgical staplers (480, 500) described below have alternative configurations that conceal an anvil half release feature when the clamping lever is closed to prevent unwanted confusion between an anvil half release feature and a clamping lever release feature.

A. Linear surgical stapler having a concealable anvil release feature within the clamping lever housing

Figures 32A and 32B show an illustrative linear surgical stapler (480) that is similar to the stapler (200) described above, except as otherwise described below. The stapler (480) includes a cartridge half (482) and an anvil half (484) configured to releasably engage each other to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. The cartridge half (482) includes an elongated cartridge channel (486), a clamping lever (488) pivotally coupled to the cartridge channel (486), and a firing unit (490) slidably supported by the cartridge channel (486). The clamping lever (488) includes a clamping lever engaging member (492) configured to releasably hold the clamping lever (488) in the closed position. The clamping lever (488) includes a clamping lever wrap (489), and the anvil half (484) includes an anvil wrap (485).

The cartridge half (482) further includes, among other features, an anvil engaging member (494) configured to releasably couple a proximal end of the cartridge half (482) with a proximal end of the anvil half (484), similar to the anvil engaging member (302) described above. The anvil engaging member (494) includes an anvil release button (496) exposed through a base wall of the cartridge channel (486). An operator may actuate the anvil release button (496) to disengage the anvil engaging member (494) from the anvil half (484) and thereby allow separation of the stapler halves (482, 484). As shown, a proximal end of the clamping lever housing (489) is shaped to conceal the anvil release button (496) within the interior of the housing (489) when the clamping lever (488) is in the closed position. Accordingly, an operator is prevented from inadvertently actuating the anvil release button (496) prior to initially actuating the clamping lever engaging member (492) to open the clamping lever (488).

B. Linear surgical stapler having a concealable anvil release feature via a tab or holding lever sleeve

Figures 33A and 33B show another illustrative linear surgical stapler (500) that is similar to the stapler (480) described above, except as otherwise described below. The stapler (500) includes a cartridge half (502) and an anvil half (504) configured to releasably engage each other to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. The cartridge half (502) includes an elongated cartridge channel (506), a clamping lever (508) pivotally coupled to the cartridge channel (506), and a firing unit (510) slidably supported by the cartridge channel (506). The clamping lever (508) includes a clamping lever engaging member (512) configured to releasably hold the clamping lever (508) in the closed position. The clamping lever (508) includes a clamping lever wrap (514), and the anvil half (504) includes an anvil wrap (516). The clamping lever wrap (514) includes an elongated tab (518) disposed at a proximal end thereof and extending transversely toward a proximal end of the anvil wrap (516). The proximal end of the anvil wrap (516) includes a cutout (520) configured to receive a free end of the tab (518) when the clamping lever (508) is closed, as shown in Figure 33B.

The cartridge half (502) further includes, among other features, an anvil engaging member (522) configured to releasably engage a proximal end of the cartridge half (502) with a proximal end of the anvil half (504), similar to the anvil engaging member (494). The anvil engaging member (522) includes an anvil release button (524) exposed through a proximal end of the cartridge channel (506). An operator may actuate the anvil release button (524) to disengage the anvil engaging member (522) from the anvil half (504) and thereby allow separation of the stapler halves (502, 504). As shown, the proximal tab (518) of the clamping lever housing (514) is configured to extend proximally around and thereby obscure the anvil release button (524) when the clamping lever (508) is in the closed position where the tab (518) is received within the anvil housing cutout (520). Accordingly, an operator is prevented from inadvertently actuating the anvil release button (524) prior to initially actuating the clamping lever engaging member (512) to open the clamping lever (508).

In some embodiments, the staplers (480, 500) may further include a clamp lever locking feature (not shown) that prevents the clamp lever engaging member (492, 512) from being released from the cartridge channel (486, 506) until the firing unit (490, 510) has returned to its proximal home position. In some embodiments, such a locking feature may be configured similar to the proximal hook (326) of the retainer member (304) described above.

VI. Illustrative linear surgical stapler having a trigger unit with traction for firing

In many instances, it is desirable to configure a linear surgical stapler to minimize the input force required by an operator to fire the stapler. The illustrative linear surgical stapler (530) shown in Figure 34 includes a firing unit (536) that is fired by pulling an actuator (538) with a tension force rather than pushing the actuator (538) with a compression force. As described in greater detail below, this “pull” configuration provides an improved mechanical advantage while maintaining duplex firing capability.

The linear surgical stapler (530) is similar to the stapler (200) in that the stapler (530) includes a cartridge half (532) and an anvil half (534) configured to releasably engage each other to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. The cartridge half (532) includes a firing unit (536) having an actuator (538) (or “firing knob”) disposed at the proximal end of the stapler (530) and attached to the proximal end of an elongated drive beam (540). The drive beam (540) extends distally to the cartridge half (532) and is in the form of a rack having a plurality of gear teeth (not shown) disposed thereon. The firing unit (536) further includes an elongated firing beam (542) extending distally through the cartridge half (532) and terminating in a distal blade element (544) configured to translate through a staple cartridge (546) to sever tissue. A proximal portion of the firing beam (542) comprises a rack (548) having a plurality of gear teeth (not shown) disposed on an upper side thereof. Although not shown, the firing beam (542) may further include one or more additional structures providing cam ramps configured to actuate staple pushers (not shown) of the staple cartridge (546), similar to the side beams (358) and cam ramps (360) of the stapler (200), for example.

The drive rack (540) and the knife rack (548) are operatively coupled to each other by a compound pinion gear (550) rotatably mounted within the cartridge half (532). The compound pinion gear (550) includes an outer gear portion (552) having a first diameter and an inner gear portion (554) concentrically disposed on a side face of the outer gear portion (552) and having a second, smaller diameter. The compound pinion gear (550) is mounted within the cartridge half (532) such that the outer gear portion engages the drive rack (540) and the inner gear portion (554) simultaneously engages the knife rack (548), and such that the pinion gear (550) is configured to rotate about an axis extending transversely to a longitudinal axis of the stapler (530).

To fire the stapler 530, an operator proximally pulls the actuator 538 from a distal home position to thereby proximally move the drive rack 540. This causes the compound pinion 550 to rotate in a first direction (e.g., counterclockwise in the view of FIG. 34) which drives the firing beam 542 distally such that the blade member 544 and cam ramps (not shown) are driven distally through the staple cartridge 546 to simultaneously sever and staple tissue trapped between the stapler halves 532, 534. After reaching its fully proximal position, the actuator (538) is then pushed distally to rotate the compound pinion (550) in a second, opposite direction (e.g., clockwise in the view of Figure 34) and thereby retract the firing beam (542) proximally to its initial position.

The power transmission between the racks (540, 548) and the compound pinion gear (550) described above produces an output force on the blade element (544) that is greater than the input force exerted on the actuator (538) by the operator, thereby providing the firing unit (536) with a mechanical advantage. It will be appreciated that the outer and inner gear portions (552, 554) of the compound pinion gear (550) may be sized to provide the firing unit (536) with any desired degree of mechanical advantage during operation.

VII. Illustrative union of the anvil plate to the anvil canal

As described above in connection with the linear surgical stapler 200, the distal jaw portion 264 of the anvil channel 260 supports an anvil surface 272 providing a plurality of staple-forming pockets. In some instances, it may be desirable to form the anvil surface 272 separately from the anvil channel 260 into an anvil plate, and then rigidly attach the anvil plate to the distal jaw portion 264. Figures 37A-39 show illustrative variations of such a process.

Figures 37A and 37B show an anvil channel (560) having a jaw distal portion (562), and an anvil surface in the form of an anvil plate (570) formed separately from the anvil channel (560). The anvil channel (560) may be similar to the anvil channel (260) described above, and the anvil channel (560) and anvil plate (570) are suitable for use with a linear surgical stapler (200). The anvil plate (570) includes a plurality of staple-forming pockets (572) and a longitudinal blade slot (574) configured to slidably receive a blade element (not shown) therethrough, which may be similar to the blade element (366) described above. The features of the anvil plate (570), including the staple-forming pockets (572) and the longitudinal blade slot (574), may be formed by one or more suitable machining processes, such as electrochemical machining (ECM) and/or coining, for example.

As shown in Figures 37A and 37B, after at least staple-forming pockets (572) have been formed in the anvil plate (570), a bottom surface (570) of the anvil plate is aligned with and lowered onto the side rails (564) of the distal jaw portion (562) of the anvil channel (560). The anvil plate (570) may be provided with one or more mating features during its machining process that assist in aligning the anvil plate (570) with the side rails (564) of the anvil channel. Such mating features may be in the form of, or alternatively, may be provided in addition to existing features of the anvil plate (570). For example, in some embodiments, such attachment features may comprise one or more of the bottom surfaces of the anvil plate (570), a longitudinal blade slot (574) or one or more selected portions of the blade slot (574), or a proximal edge of the anvil plate (570).

Once the anvil plate (570) is mounted to the distal side rails (564) of the anvil channel (560), the anvil plate (570) is securely attached to the side rails (564). Figure 38 shows a first illustrative joining method in which each side edge of the anvil plate (570) is secured to the side rail (564) of the respective anvil channel with a plurality of spot welds (580) longitudinally spaced apart from each other. Figure 39 shows a second illustrative joining method in which each side edge of the anvil plate (570) is secured to the side rail (564) of the respective anvil channel with a seam weld (582) that extends longitudinally for substantially the entire length of the anvil plate (570). In other embodiments, a plurality of shorter seam welds (582) may be provided along each side edge of the anvil plate (570), or a combination of spot welds (580) and seam welds (582) may be provided. Furthermore, the longitudinal knife slot (574) may be formed in the anvil plate (570) before or after joining the anvil plate (570) to the anvil channel (560). It will be appreciated that forming pockets (572) in the anvil plate (570) prior to joining the anvil plate (570) to the anvil channel (560) advantageously reduces the size of the component being manipulated during the pocketing process, thereby simplifying and reducing manufacturing costs of the anvil half of a respective linear surgical stapler.

IX. Miscellaneous

It should be understood that one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with one or more of the other teachings, expressions, embodiments, examples, etc. described herein. Therefore, the teachings, expressions, embodiments, examples, etc. described above should not be considered in isolation from one another. The various suitable ways in which the teachings herein may be combined will be readily apparent to those skilled in the art in view of the teachings herein.

Furthermore, one or more of the teachings, expressions, embodiments, examples, etc., described herein may be combined with one or more of the teachings, expressions, embodiments, examples, etc. described in patent application No. US-2019/0239881 A1, entitled “Release Mechanism for Linear Surgical Staple”; patent application No. US-2019/0239882 A1, entitled “Lockout Assembly for Linear Surgical Stapler”; patent application No. US-2019/0239886 A1, entitled “Features to Align and Close Linear Surgical Stapler”; patent application No. US-2019/0239883 A1, entitled “Releasable Coupling Features for Proximal Portions of Linear Surgical Stapler”; Patent application no. US-2019/0239884 A1, entitled “Firing Lever Assembly for Linear Surgical Stapler”; and/or patent application no. US-2019/0239885 A1, entitled “Clamping Mechanism for Linear Surgical Stapler”.

Versions of the devices described above may be applicable to conventional medical treatments and procedures performed by a medical professional, as well as to robotic-assisted medical treatments and procedures. By way of example only, various teachings herein may be readily incorporated into a robotic surgical system such as the DAVINCI™ system from Intuitive Surgical, Inc. of Sunnyvale, California.

Versions of the devices described above may be designed to be discarded after a single use, or they may be designed to be used multiple times. The versions may, in one or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular parts, and subsequent reassembly. In particular, some versions of the device may be disassembled, and any number of particular parts or portions of the device may be selectively replaced or removed in any combination. Following cleaning and/or replacement of particular parts, some versions of the device may be reassembled for subsequent use, either in a reconditioning facility or by a user immediately prior to a procedure. Those skilled in the art will appreciate that reconditioning a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. The use of such techniques and the resulting reconditioned device are all within the scope of the present application.

By way of example only, the embodiments described herein may be sterilized before and/or after a procedure. In one sterilization technique, the device is placed in a closed and sealed container, such as a plastic bag or TYVEK. The container and device may then be placed in a radiation field that can penetrate the container, such as gamma radiation, X-rays, or high-energy electrons. The radiation may kill bacteria on the device and in the container. The sterilized device may then be stored in the sterile container for later use. A device may also be sterilized using any other technique known in the art, including, but not limited to, beta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention, other adaptations of the methods and systems described herein can be made by appropriate modifications by one skilled in the art without departing from the scope of the present invention as defined in the claims. Several such possible modifications have been mentioned, and others will be apparent to those skilled in the art. For example, the examples, embodiments, geometry, materials, dimensions, proportions, steps, and the like described above are illustrative and not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

Claims (13)

i. A surgical stapler (200), comprising: (a) a first elongated element (204) having a distal portion (264) supporting an anvil surface (272), wherein the anvil surface (272) includes a plurality of staple-forming pockets; (b) a second elongated element (202) having a distal portion (210) configured to receive a staple cartridge (230); (c) a clamping element (240) operable to releasably clamp the first elongated element (204) against the second elongated element (202); (c) a firing unit (350), wherein the firing unit (350) is translatable from a first longitudinal position to a second longitudinal position to fire the staple cartridge (230) when the first elongated member (204) is held against the second elongated member (202); and (d) a retention unit (300), wherein the retention unit (300) comprises: (i) a first retaining element (302) configured to releasably engage a proximal end of the first elongated element (204) with a proximal end of the second elongated element (202), and (ii) a second retaining element (304) configured to releasably retain the firing unit (350) in the first longitudinal position, wherein characterized in that: the first retaining element (302) comprises a latching element, wherein the second retaining element (304) comprises a detent element, wherein the clamping element (240) is movable from an unclamped position to a clamped position to clamp the first elongated element (204) against the second elongated element (202), wherein the detent element (304) is configured to prevent the clamping element (240) from returning to the unclamped position from the clamped position when the firing unit (350) is longitudinally advanced away from its first longitudinal position. 2. The surgical stapler of claim 1, wherein the retention unit (300) is disposed at a proximal end of the second elongated element (202). 3. The surgical stapler of claim 1 or claim 2, wherein the first retaining element (302) is movable relative to the second retaining element (304). 4. The surgical stapler of any one of the preceding claims, wherein the first retaining element (302) is configured to rotate in a first direction to release the proximal end of the first elongated element (204) from the proximal end of the second elongated element (202), wherein the second retaining element (304) is configured to rotate in a second direction to release the firing unit (350) from the first longitudinal position. 5. The surgical stapler of claim 4, wherein the retention unit (300) further comprises a flexible element (340) configured to bias the first retention element (302) in the second direction and, simultaneously, bias the second retention element (304) in the first direction. 6. The surgical stapler of any one of the preceding claims, wherein the first retaining element (302) and the second retaining element (304) are configured to rotate with respect to the channel (206) of the second elongated element around the same axis of rotation. 7. The surgical stapler of claim 6, wherein the axis of rotation extends transversely to a longitudinal axis of the surgical stapler (200). 8. The surgical stapler of claim 1, further comprising a projection (270) disposed at a proximal end of the first elongated element (204), wherein the engaging element (302) is configured to releasably capture the projection (270) to thereby couple the proximal end of the first elongated element (204) with the proximal end of the second elongated element (202). 9. The surgical stapler of claim 8, wherein the first elongated element (204) is configured to rotate relative to the second elongated element (202) about the projection (270) when the proximal end of the first elongated element (204) engages the proximal end of the second elongated element (202). 10. The surgical stapler of any one of claims 1 to 9, wherein the clamping element (240) is movable from an unclamped position to a clamped position to clamp the first elongated element (204) against the second elongated element (202), wherein the retention unit (300) further comprises a release feature (312) that is operable to actuate the engaging element (302) to release the proximal end of the first elongated element (204) from the proximal end of the second elongated element (202), wherein the release feature (312) is exposed when the clamping element (240) is in the unclamped position, wherein the release feature (312) is concealed when the clamping element (240) is in the clamped position. 11. The surgical stapler of any one of claims 1 to 10, wherein the retainer element (304) includes a distally extending projection (324) configured to releasably engage a proximal end (372) of the firing unit (350). 12. The surgical stapler of claim 1, wherein the detent member (304) includes a locking feature (326) configured to engage a proximal feature (255) of the clamping member (240) to prevent the clamping member (240) from returning to the unclamped position from the clamped position when the firing unit (350) is longitudinally advanced away from its first longitudinal position. 13. The surgical stapler of claim 12, wherein the proximal feature (255) of the clamping element (240) comprises a second engaging element (254), wherein the second engaging element (254) is operable to releasably engage a proximal end of the clamping element (240) with the second elongated element (202) when the clamping element (240) is in the clamping position, wherein the locking feature (326) is operable to prevent the second engaging element (254) from disengaging from the second elongated element (202) when the firing unit (350) is longitudinally advanced away from its first longitudinal position.